Physics
posted by Brianb .
What size motor [W] is required to pump 12,000 gallons of water up a water tower (with a height of 25 ft.) in 25 minutes? The density of water is 1,000 kg/cubic meter.

Convert gallons/min to kg/second.
Then multiply the kg/s pumping rate by g*(height). That will equal the rate potential energy is added to the water, in watts.
You should do the calculation.